A

It is used before words beginning with a consonant sound.a boy, a woman, a unit (yunit), a one-rupee note (wun)

An

It is used before words beginning with a vowel sound.an eye, an umbrella, an hour (h is silent), an heir (h is silent)

DEFINITE ARTICLE

The Definite Article is used to specify a particular or definite person or thing.

USAGE

To refer to some PARTICULAR person or thingCall the girl standing outside.

To indicate a WHOLE CLASS with a Singular NounThe lion is a fierce animal.

As an ADVERBThe more, the merrier.The fewer, the better.

Before RIVERS, MOUNTAIN RANGES (not individual mountains) and GROUPS OF ISLANDSThe Ganges, the Indus, the ThamesThe Himalayas, the Alps (not the Mount Everest)The British Isles, the Lakshadweep Islands

Before OCEANS, GULFS, SEAS, and BAYSThe Indian Ocean, the Atlantic Ocean, the Red Sea, the Arabian Sea, the Bay of Bengal, the Persian Gulf.

Before the names of some PROVINCES, COUNTRIES, etc.The United States of America, the United Kingdom, the Czech Republic, the Deccan

Before the names of WELL-KNOWN BOOKSThe Bible, the Vedas, the Koran, the Ramayan

Before the names of NEWSPAPERS, MAGAZINES, etc.The Times of India, the New York Times, the Hindustan Times

Before the names of PUBLIC BUILDINGS, INSTITUTIONS, ASSOCIATIONS, etc.The Taj Mahal, the University of London, the United Nations

Before the names of PEOPLES (NATIONS), FAMILIES and ADJECTIVES formed from Proper NounsThe English language, the Turkish tobacco, the French, the Chinese, the Gandhis, the Hindus

To use a COMMON NOUN as an ABSTRACT NOUNHe played the fool. (foolishness)The mother in her was aroused. (motherly feeling)

Before ORDINALS and SUPERLATIVESThe fifteenth of October, the third occasion, the seventh timeIt was the hottest day of the year.

Before a PROPER NOUN qualified by an Adjective or an Adjective phrase/clauseThe immortal Shakespeare, the wise Solomon, the great Caeser

Before an ADJECTIVE used as a NOUNThe poor depend on the rich.The wise hate the foolish.

Before COMMON NOUNS which are UNIQUEThe sun, the moon, the earth, the sky

Omission of Articles

Before Common Nouns used in the widest sense.Man is mortal.

Before Proper NounsMumbai is a big city.Ashoka was a kind ruler.

Before Abstract Nouns used in a general senseHonesty is the best policy.NOTE: THE is used only when it is qualified by an adjective.

Before Material Nouns (unless specifying a particular piece of metal)Gold is a precious metal.Iron is a chemical element.